Hexadecane content

Myristic acid from hexanoic acid and methyl hydrogen sebacate). Dissolve 23 -2 g. of redistilled hexanoic acid (re caproic acid), b.p. 204-6-205-5°/760 mm., and 21-6 g. of methyl hydrogen sebacate in 200 ml. of absolute methanol to which 0 13 g. of sodium has been added. Electrolyse at 2 0 amps., whilst maintaining the temperature between 30° and 40°, until the pH is about 8 0 (ca. 6 hours). Neutralise the contents of the electrolysis cell with a little acetic acid and distil off the methyl alcohol on a water bath. Dissolve the residue in 200 ml. of ether, wash with three 50 ml. portions of saturated sodium bicarbonate solution, once with water, dry with anhydrous magnesium sulphate, and distil with the aid of a fractionating column (see under Methyl hydrogen adipate). Collect the re-decane at 60°/10 mm. (3 0 g.), the methyl myristate at 158-160°/ 10 mm. (12 5g.) and dimethyl hexadecane-1 16-dicarboxylate at 215-230°/ 7 mm. (1 -5 g.)... 

P. phosphoreum. In the case of A. fischeri, the total amount of aldehydes was only 15% of that from P. phosphoreum, which consisted of dodecanal (36%), tetradecanal (32%) and hexadecanal (20%). The contents of aldehydes having the carbon atoms of 10, 11, 13, 15, 17 and 18 were negligibly small in both bacterial species. 

Volatilization of an organic mixture of contaminants, distributed vertically in the subsurface, may induce not only a decrease in the component concentrations but also an enrichment of the deeper layers during the volatilization process. Figure 8.13 shows the actual content of three representative hydrocarbons—m-xylene (C ), n-decane (Cj ,), and hexadcane (Cj )—which originated from the applied kerosene found along a 20 cm soil column, 18 days after application on dry soil. Roughly 30% of the initial content of m-xylene still remained in the soil after 18 days. Furthermore, the content of m-xylene increased somewhat after the third day a similar trend was found for the n-decane distribution. Hexadecane was partially removed from deeper layers and redistributed near the soil surface. 

Figure 1 demonstrates the drastic influence on the stability region of a lamellar liquid crystalline phase when an aromatic hydrocarbon is substituted by an aliphatic one. The lamellar phase formed by water and emulsifier is stable between 20 and 60 wt % water. Addition of an aromatic hydrocarbon (p-xylene) to the liquid crystalline phase increased the maximum amount of water from 45 to 85% (w/w) (Figure 1 left). Inclusion of an aliphatic hydrocarbon (n-hexadecane) gave the opposite result the maximum water content in the liquid crystalline state was reduced (right). Some of the factors which govern the association behavior of these surfactants and cause effects such as the one above are treated below. 

Cotterman et al. (34) showed that hexadecane-cracking activity of AFS and USY zeolites appeared to be a function of total Al content, independent of method of dealumination, implying that hexadecane cracking occurs over both framework- and extra-framework-acid sites. Hence, extra-framework material in mildly steamed synthetic faujasite, USY, makes a significant contribution to catalyst activity, as previously reported (32). Gasoline selectivity is influenced by both the method of dealumination and steam treatment, and depends on both framework-acid sites and the presence of extra-framework material. 

The change in nature of the oxidized surface can be followed with immersion liquids other than water. By increasing the oxygen content of a carbon black (Le. Spheron 6) up to 12%, Robert and Brusset (1965) obtained an increase of the energy of immersion in methanol from 140 to as much as 390 mJ nT2 (practically the same ratio as that observed with water), whereas the energy of immersion in n-hexadecane remained nearly constant, around 100 mJ m-2. 

Dealuminated Y zeolites which have been prepared by hydrothermal and chemical treatments show differences in catalytic performance when tested fresh however, these differences disappear after the zeolites have been steamed. The catalytic behavior of fresh and steamed zeolites is directly related to zeolite structural and chemical characteristics. Such characteristics determine the strength and density of acid sites for catalytic cracking. Dealuminated zeolites were characterized using X-ray diffraction, porosimetry, solid-state NMR and elemental analysis. Hexadecane cracking was used as a probe reaction to determine catalytic properties. Cracking activity was found to be proportional to total aluminum content in the zeolite. Product selectivity was dependent on unit cell size, presence of extraframework alumina and spatial distribution of active sites. The results from this study elucidate the role that zeolite structure plays in determining catalytic performance. 

Catalyst Performance Relationships. Hexadecane cracking activity of AFS and USY zeolites, when corrected for deactivation effects, shows little or no dependence on framework composition. Rather, as shown in Figure 6, activity appears to be a function of total aluminum content independent of the method of dealumination. This result implies that hexadecane cracking occurs over both framework and extraframework acid sites and that it is the total number of such sites which determines catalytic activity. Hence, extraframework material in the USY samples makes a significant contribution to catalyst activity as reported by others(18.19). 

Hexadecane cracking activity correlates with total aluminum content USY materials are more active than AFS materials before and after steaming. Extraframework aluminum contributes to catalytic cracking activity. 

Catalysts and their demineralisation. The FCC catalysts were typical commercial formulations and the deactivated sanmles were obtained from units processing (i) a heavy feedstock containing ca 1.5% sulphur, a Conradson carbon content of 5.0% w/w and Ni and V contents of 5 ppm each and (ii) a HVGO containing only 0.1% sulphur and below 2 ppm of Ni and V. The catalyst samples deactivated in the MAT reactorwerefrom a series runs with n-hexadecane as the base feed with either phenanthrene or quinoline as a co-feed present at concentrations of 1 and 10% v/v (11, 12). The all-silica laboratory-scale fluidised-bed reactor used had a 4 cm diameter bed and, during each run, oz 30 g n-hexadecane was fed into the reactor containing 80 g of catalyst. 

The tar content was collected by condensation followed by two subsequent impinger bottles with acetone. Quantitative determination was performed by addition of hexadecane as internal standard to this acetone solution. Non-polar components in the acetone-tar solution were extracted to a dichloromelhane solution and subsequently analysed using gas chromatography (FID-detector and separation on a 30m, 0.32 mm ID, fused silica DB-5 column with 0,25 pm stationary phase). 

Hexadecane Pd/Zr02 coated on metal foil from Catacel Corp. 600-900 3-6 22,000 Improved catalytic performance has been observed at higher S/C ratio, higher temperature, and feed containing lower sulfur content Goud et al.141... 

A complex variation in the spectra of hexadecane is observed as a function of the oil content of the liquid crystal with a water ratio of 40 60 (Fig. 2), the main features being as follows ... 

These are illustrated in Figure 3 as a plot of quadrupolar splittings versus oil content for hexadecane. 

Figure 2. Deuterium NMR spectra of n-hexadecane-dg solubilized in a lamellar dispersion of C12E4/H2O as a function of oil content (the numbers are weight fraction of oil) at a fixed soap.water ratio (60 40 W/W).

The effect of quinoline and phenanthrene additions to a n-hexadecane feedstock has been determined for a model four-component FCC catalyst by means of a MAT reactor with analysis of all products and characterisation of the coke produced. Both additions lead to an overall loss in conversion quinoline is considered to act as a poison while phenanthrene participates strongly in coke formation and the resultant coke becomes more aromatic in nature. The cracking propensity and associated coke formation have been measured for a series of FCC catalysts with differing compositions. Increasing amounts of zeolite in a matrix lead to increasing extents of conversion but with little effect on the extent of coke production. However, a pure zeolite gave a very high coke content. 

Coke deposits were studied using mass spectra obtmed from the probe El and Cl analyses of the deactivated catalysts arising from the various feed streams. Alkane and alkene fragments were observed to dominate the individual mass spectra (particularly, m/z 57, 71 and 55, 69, respectively, in the El mode). Although alkylaromatics were evident for the catalyst from the tests with n-hexadecane and the n-hexadecane/phenanthrene mixture PACs are only present in trace quantities. Quinoline addition gave rise to much less intense ions from the deactivated catalyst due to its lower carbon content and the reduced sensitivity made it difBcult to observe the aromatic fragments. Indeed, the most intense peak was from quinoline itself (m/z 129 El, 130 Cl). 

The oil and grease content of the refinery wastewater effluent C was determined by the partition infrared method (5520 C) according to Standard Methods (1995). A mixture, by volume, of 37.5% iso-octane, 37.5% hexadecane and 25.0% benzene was used as the reference oil and infrared absorbance was determined using a Perkin-Elmer 881 infrared spectrophotometer. 

In contrast to the results obtained with hexadecane, the addition of squalane to the O/W nanoemulsion system based on isohexadecane showed a systematic decrease in Ostwald ripening rate as the squalene content was increased. The results are included in Figure 14.14, which shows plots of versus time for nanoemulsions containing varying amounts of squalane. The addition of squalane up to 20% based on the oil phase showed a systematic reduction in ripening rate (from 8.0 to 4.1 x 10 m s i). It should be noted that when squalane alone was used as the oil phase, the system was very unstable and showed creaming within 1 h. The results also showed that the surfactant used was unsuitable for the emulsification of squalane. 

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